Remember those really bad movies in the 50s and 60s where something not quite dead had not the sense to die and kept troubling innocent humans? Well, M$’s EULA has been found to be so by a court of law. If the EULA says you cannot resell the licence/CD/whatever, you cannot.
Get this. You pay M$ or someone $X for the use of that other OS or Office forever but you may not legally break forever into Y years for you and forever – Y years for someone else if the EULA says it applies to one user or one PC etc. There is no justice in US courts it seems. If M$ accepts $X for use forever why should they be entitled to 2 X $X? If I buy a licence to drive my car for a year, I cannot resell it because it expires but forever might outlast me or my car. Same thing goes with a PC. If I pay for forever and the thing goes belly-up in a few weeks through infant mortality, am I denied the use of that software for which I paid because the machine died? That’s not right. I should be able to sell the CDs on eBay and go on with my life without that PC if I choose. Why does M$ get to insist that I buy a new PC if I do not want to. Why do they get the right to charge for forever and only deliver a few weeks?
All the more reason to never use that other OS. The GNU Public Licence which covers most of GNU/Linux frees you from so many restrictions. You can use it forever if you want or pass it on or copy it etc. Use Free Software. Use GNU/Linux.